The overall objectives of this research are concerned with three areas of investigation. The first is the determination of the bio-chemical and physiological factors that influence the synthesis and structure of triglycerides in adipose tissue. Starting with the whole animal, our research has progressed to isolated tissues, and now, at the enzymatic level, the control of structure and rate of triglyceride synthesis is under investigation. The second is the elucidation of the mechanism of the reactions involved in the biohydrogenation of unsaturated fatty acids by anaerobic bacteria. This encompasses two systems: (a) the hydrogenation of a polyenoic fatty acid to a monoenoic fatty acid, and (b) the hydrogenation of the monoenoic acid to a saturated acid. The first process is being studied at the enzyme level, while investigation of the second process is largely a bacteriological problem, in that the organism(s) responsible remains to be cultured and identified. The third area involves a study of the etiology of saturated fat toxicity. Currently this problem is under investigation by way of a nutritional approach.